Verizon is requiring users to make changes to their email application parameters. Verizon's webpage info regarding Apple's Mail on Macs and on iPhones is somewhat out of date, pertaining to earlier versions of those apps. You may find menus and controls that are shown in the instructions do not exist or are very different on your system. Verizon's live tech assistance is of no value here. Contact Apple's Live Help via their website; they will call you and, if necessary, set up temporary tech-control of your system to help you make the necessary changes to Mail. Hint: First have Verizon's email msg regarding the required changes posted on your screen so that the Apple tech can refer to it. The one-shot help may cost you $20 if you don't have a current maintance plan, but the quality of their help is excellent (30-day follow-up assistance is included in that cost).